CN115148037A

CN115148037A - Driving support device

Info

Publication number: CN115148037A
Application number: CN202210157372.XA
Authority: CN
Inventors: 镰仓宏
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2021-03-30
Filing date: 2022-02-21
Publication date: 2022-10-04
Also published as: JP2022153836A; US20220319317A1

Abstract

The present invention provides a driving assistance device, including: an information acquisition unit that acquires traffic signal information including switching information of the traffic signal (201), position information indicating the position of the vehicle relative to the traffic signal (201), and rear vehicle information including length information of a rear vehicle traveling behind the vehicle; a length calculation unit (22) that calculates the overall length from the front end of the host vehicle to the rear end of the rear vehicle on the basis of the length information of the rear vehicle; a derivation unit (23) that derives, on the basis of the traffic signal information, the position information, and the overall length, driving assistance information including a target vehicle speed or a target acceleration of the vehicle, for the entire vehicle including the vehicle and the rear vehicle to pass through or stop at a point where the traffic signal (201) is installed; and an output unit (25) that transmits, to a rear vehicle, vehicle information including information that the vehicle has a driving assistance function.

Description

Driving support device

Technical Field

The present invention relates to a driving assistance device that assists driving of a driver.

Background

As such an apparatus, the following apparatus has been known: the start timing of the accelerator release operation is reported to a driver of a vehicle traveling on a road on which a traffic signal is provided, based on traffic signal information received by the vehicle. Such a device is described in patent document 1, for example. In the device described in patent document 1, a timing of a deceleration operation that enables a driver to pass through an intersection where a traffic light is installed without stopping the vehicle is reported to the driver via a display unit.

However, when there is a rear vehicle that does not have such a driving assistance function behind the host vehicle having the driving assistance function based on the traffic signal information, the driver of the rear vehicle may feel uncomfortable when the host vehicle decelerates based on the traffic signal information.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-096016 (JP 2014-096016A).

Disclosure of Invention

A driving assistance device according to an aspect of the present invention includes: a communication unit; a traffic signal information acquisition unit that acquires traffic signal information including switching information of a traffic signal via a communication means; a position information acquisition unit that acquires position information indicating a position of a vehicle relative to a traffic signal; a rear vehicle information acquisition unit that acquires rear vehicle information including length information of a rear vehicle traveling behind a host vehicle via a communication unit; a length calculation unit that calculates an overall length from a front end of the host vehicle to a rear end of the rear vehicle, based on the length information of the rear vehicle acquired by the rear vehicle information acquisition unit; an deriving unit that derives driving assistance information including a target vehicle speed or a target acceleration of the vehicle, which is used for the entire vehicle including the vehicle and the rear vehicle to pass through or stop at a point where the traffic signal is installed, based on the traffic signal information acquired by the traffic signal information acquiring unit, the position information acquired by the position information acquiring unit, and the entire length calculated by the length calculating unit; and an output unit that transmits, to the rear vehicle via the communication unit, own vehicle information including information that the own vehicle has a driving assistance function for deriving the driving assistance information.

Drawings

The objects, features and advantages of the present invention are further clarified by the following description of the embodiments in relation to the accompanying drawings.

Fig. 1 is a side view schematically showing an example of a driving scene of a vehicle including a driving assistance device according to an embodiment of the present invention.

Fig. 2A is a plan view schematically showing an example of a driving scene of a vehicle including a driving assistance device according to an embodiment of the present invention.

Fig. 2B is a plan view schematically showing another example of a driving scene of a vehicle including the driving assistance device according to the embodiment of the present invention.

Fig. 3 is a block diagram showing a main part configuration of the driving assistance device according to the embodiment of the present invention.

Fig. 4 is a diagram illustrating an example of the operation of a vehicle provided with a driving assistance device according to an embodiment of the present invention.

Fig. 5 is a flowchart showing an example of processing executed by the controller of fig. 3.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to fig. 1 to 5. Fig. 1 is a diagram showing an example of a traveling scene of a vehicle (referred to as a host vehicle for distinguishing from other vehicles) provided with a driving assistance device according to the present embodiment. As shown in fig. 1, the vehicle 100 includes an in-vehicle device 100a. The vehicle-mounted device 100a has a driving assistance function of acquiring traffic signal information such as switching information of a traffic signal 201 provided in front of the communication device 200 from the communication device 200 provided on the road and reporting target vehicle speed information to the driver based on the traffic signal information.

The target vehicle speed information includes a target vehicle speed range in which the vehicle 100 can pass through an intersection where the traffic signal 201 is installed without stopping, information of a target acceleration, or information of a target deceleration for smoothly stopping the vehicle 100 in front of the traffic signal 201. The traffic signal is configured to be sequentially switched to red indicating a stop command, green indicating that travel is possible, and yellow indicating that travel is possible when it is difficult to safely stop the vehicle, at a predetermined cycle. The traffic signal may be an arrow traffic signal in which a direction in which the traffic signal can travel is indicated by an arrow.

The vehicle-mounted device 100a is configured to be able to communicate with other vehicles around the host vehicle 100, in particular, the vehicle-mounted

devices

101a and 102a of the

rear vehicles

101 and 102 traveling behind the host vehicle 100, respectively, i.e., to be able to perform inter-vehicle communication, via the communication means. Fig. 2A and 2B are plan views each showing an example of a traveling scene of the host vehicle 100. In particular, fig. 2A shows an example in which the light color of the traffic signal 201 in front of the host vehicle 100 is green and the host vehicle 100 passes through an intersection where the traffic signal 201 is installed, and fig. 2B shows an example in which the light color of the traffic signal 201 is red and the host vehicle 100 is about to stop at the stop line 202 in front of the traffic signal 201.

As shown in fig. 2A and 2B, the

rear vehicles

101 and 102 are vehicles that are located behind the host vehicle 100 on the same travel lane as the host vehicle 100 and travel in conjunction with the host vehicle 100. For example, the vehicle is a vehicle that travels following a preceding vehicle while maintaining a predetermined inter-vehicle distance from the preceding vehicle. Note that, the vehicle 100 is a front vehicle in the case of the rear vehicle 101, and the vehicle 101 is a front vehicle in the case of the rear vehicle 102.

Fig. 2A and 2B schematically show a state in which the host vehicle 100 and the

rear vehicles

101 and 102 located within a predetermined distance from each other are performing inter-vehicle communication by a two-dot chain line. The

rear vehicles

101 and 102 have a communication function capable of inter-vehicle communication, but do not have a function of acquiring traffic signal information from the communication device 200 as in the case of the host vehicle 100.

The

rear vehicles

101 and 102 traveling in conjunction with the host vehicle 100 are not limited to 2, and may be 1 or 3 or more. For example, all the vehicles that are traveling in the same lane as the host vehicle 100 and that are provided so as to be able to perform inter-vehicle communication with the host vehicle 100 and that are located within a first prescribed distance from the host vehicle 100 are rear vehicles. The following vehicles may be the entire vehicles sequentially connected to the host vehicle 100, with the inter-vehicle distance from the preceding vehicle within the second predetermined distance. The entire vehicle 100 and the

rear vehicles

101 and 102, that is, a single group including the vehicle 100 and the

rear vehicles

101 and 102 is referred to as a vehicle group 110.

The vehicle 100 has a driving assistance function of reporting a target vehicle speed and the like based on the traffic signal information, and thus can travel with the switching of the traffic signal 201 predicted. For example, even if the traffic signal 201 in front is currently green, when the own vehicle 100 is switched from green to yellow before reaching the point where the traffic signal 201 is provided, a deceleration command of the own vehicle 100 is reported. The driver performs a deceleration operation in accordance with the command, thereby smoothly decelerating the host vehicle 100.

On the other hand, since the

rear vehicles

101 and 102 do not have such a driving assistance function, if the traffic signal 201 in front is green and the host vehicle 100 in front decelerates, the drivers of the

rear vehicles

101 and 102 may feel uncomfortable. Therefore, in order not to cause the driver of the

rear vehicles

101 and 102 to feel uncomfortable, the driving assistance device of the present embodiment is configured as follows.

Fig. 3 is a block diagram showing a main part configuration of the driving assistance device 10 of the present embodiment. The driving assistance device 10 is constituted by an in-vehicle device 100a of fig. 1. As shown in fig. 3, the driving assistance device 10 is configured with a controller 20 as a center, and includes a communication unit 11, a positioning sensor 12, a distance detector 13, and a monitor 14, which are communicably connected to the controller 20, respectively.

The communication unit 11 is configured to be capable of performing wireless communication, that is, inter-road communication, with a communication device 200 such as an optical beacon or a radio beacon installed on a road. Specifically, the communication unit 11 receives, from the communication device 200 provided on the road, traffic signal information on the traffic signal 201 located in the traveling direction of the host vehicle 100, that is, the traffic signal 201 provided at the intersection through which the host vehicle 100 passes next. The traffic signal information includes information on the position of the traffic signal 201 and information on the switching time of the light color of the traffic signal 201. The information on the switching time includes information on the remaining time until the traffic signal 201 is switched from green to yellow when it is currently green, information on the remaining time until the traffic signal 201 is switched to green when it is not currently green, and the like.

The communication unit 11 is configured to be capable of wireless communication with other vehicles around the host vehicle 100, and particularly, capable of wireless communication with the rear vehicles 101 and 102 (capable of inter-vehicle communication). The communication unit 11 receives vehicle information of the

rear vehicles

101, 102 through inter-vehicle communication. The vehicle information includes information on the lengths (overall lengths) of the

rear vehicles

101 and 102 stored in advance as information unique to the

rear vehicles

101 and 102. When the

rear vehicles

101 and 102 have position detectors such as GPS sensors, the vehicle information includes position information.

The positioning sensor 12 receives a positioning signal transmitted from a positioning satellite. The positioning satellite is an artificial satellite such as a GPS (global positioning system) satellite or a quasi-zenith satellite. The current position (latitude, longitude, and altitude) of the vehicle 100 is measured using the positioning information received by the positioning sensor 12. The positioning sensor 12 is used to detect the position of the vehicle 100 (such as the distance to the traffic light 201) relative to the position of the intersection where the traffic light 201 is installed. Therefore, a distance detector (radar, lidar, etc.) that detects the distance from the host vehicle 100 to the target object (object near the intersection) may be used instead of the positioning sensor 12.

The distance detector 13 is configured by a laser radar that detects the position of an object (distance or direction from the vehicle 100) around the vehicle 100 by irradiating laser light and detecting reflected light, a radar that detects the position of an object around the vehicle 100 by irradiating electromagnetic waves and detecting reflected waves, and the like. The distance detector 13 is provided on the rear surface of the own vehicle 100, and detects the distance from the own vehicle 100 to the rear vehicle 101. The

rear vehicles

101 and 102 also have the same distance detector, and thereby the inter-vehicle distance between the rear vehicle 101 and the rear vehicle 102 is detected.

The monitor 14 is provided on a dashboard at the front of the vehicle interior, and provides various information to the driver. The monitor 14 may be a display of a navigation unit disposed near the instrument panel. A head-up display that projects an image on a windshield or a panel provided near the windshield may be configured as the monitor 14.

The controller 20 executes predetermined processing based on signals from the communication unit 11, the positioning sensor 12, and the distance detector 13, and outputs a control signal to the monitor 14. The controller 20 includes a computer having other peripheral circuits such as a CPU (central processing unit), a ROM (read only memory), a RAM (random access memory), and an I/O (input/output) interface. The controller 20 has a functional configuration of an information acquisition unit 21, a length calculation unit 22, a driving derivation unit 23, a report control unit 24, and an output unit 25.

The information acquisition unit 21 acquires traffic signal information received by the communication unit 11, vehicle information of the

rear vehicles

101 and 102, and information (position information) of the current position of the host vehicle 100 detected by the positioning sensor 12. That is, the information acquiring unit 21 functions as a traffic signal information acquiring unit that acquires traffic signal information, a position information acquiring unit that acquires position information of the host vehicle 100, and a rear vehicle information acquiring unit that acquires vehicle information (rear vehicle information) of the

rear vehicles

101 and 102.

The length calculation unit 22 calculates the overall length L0 from the front end of the vehicle 100 to the rear end of the rear vehicle 102 located at the rear end of the vehicle group 110. Fig. 4 is a diagram schematically showing the entire length L0. As shown in fig. 4, the overall length L0 is calculated by adding the length L1 of the host vehicle 100, the inter-vehicle distance Δ L from the host vehicle 100 to the rear vehicle 102, and the length L2 of the rear vehicle 102. The length L1 is stored in the memory in advance. The length L2 is included in the vehicle information of the rear vehicle 102 acquired via the communication unit 11.

The inter-vehicle distance Δ L is calculated by adding the inter-vehicle distance Δ L1 from the host vehicle 100 to the rear vehicle 101 detected by the distance detector 13, the length Δ L2 included in the vehicle information of the rear vehicle 101 acquired via the communication unit 11, and the inter-vehicle distance Δ L3 between the

rear vehicles

101, 102 detected by the

rear vehicles

101, 102 and acquired via the communication unit 11. The length Δ L2 and the inter-vehicle distance Δ L3 of the rear vehicle 101 are acquired by the information acquiring unit 21 (rear vehicle information acquiring unit). The inter-vehicle distance Δ L is not constant but varies according to acceleration and deceleration of the host vehicle 100 or the like. Such a vehicle group 110 comprising the own vehicle 100 and the following

vehicles

101, 102 can be regarded as one large vehicle (e.g. trailer) 110a. When the

rear vehicles

101 and 102 include positioning sensors such as GPS sensors, the inter-vehicle distance Δ L may be calculated by acquiring positional information of the

rear vehicles

101 and 102 detected by the positioning sensors.

The rear vehicle assumed by the driving assistance device of the present embodiment is the rear vehicle 101 in which the inter-vehicle distance Δ L1 between the host vehicle 100 and the rear vehicle 101 is within the first predetermined distance Δ La. The vehicle-to-vehicle distance Δ L3 between the rear vehicle 101 and the rear vehicle 102 is within the second predetermined distance Δ Lb. That is, the vehicle is a rear vehicle that satisfies the inter-vehicle distance conditions of Δ L1 ≦ Δ La and Δ L3 ≦ Δ Lb. Therefore, when the inter-vehicle distance Δ L1 is greater than the first predetermined distance Δ La, the rear vehicle 101 is not regarded as a rear vehicle connected to the host vehicle 100, and the driving assistance information is not transmitted to the

rear vehicles

101 and 102 through the output unit 25 described later. When the inter-vehicle distance Δ L3 is greater than the second inter-vehicle distance Δ Lb, the rear vehicle 102 is not regarded as a rear vehicle connected to the rear vehicle 101, and the driving assistance information is not transmitted to the rear vehicle 102. The first predetermined distance Δ La and the second predetermined distance Δ Lb are equal, for example. The first predetermined distance Δ La may be greater than the second predetermined distance Δ Lb or may be smaller than the second predetermined distance Δ Lb.

The driving derivation unit 23 derives recommended driving recommended to the driver based on the traffic signal information and the position information acquired by the information acquisition unit 21 and the overall length L0 calculated by the length calculation unit 22. Specifically, the distance from the host vehicle 100 to the intersection where the traffic signal 201 is provided is calculated using the position information, and the range of the target vehicle speed at which the vehicle group 110 including the host vehicle 100 can pass through the intersection without stopping is calculated from the distance, the entire length L0 of the vehicle group 110, and the remaining time until the traffic signal 201 in front of the host vehicle 100 included in the traffic signal information is switched from green to yellow. That is, the range of the target vehicle speed in which not only the host vehicle 100 but also the

rear vehicles

101 and 102 can pass through the intersection is calculated. The target vehicle speed range is included in the recommended driving recommended to the driver.

On the other hand, when it is determined that the vehicle group 110 cannot pass through the intersection without stopping the vehicle, for example, when it is determined that the own vehicle 100 cannot pass through or the own vehicle 100 can pass through but the rear vehicle 102 cannot pass through, the driving derivation unit 23 calculates the range of the target vehicle speed for the own vehicle 100 to smoothly stop in front of the traffic signal 201. When the current vehicle speed of the host vehicle 100 exceeds the target vehicle speed, a deceleration command is derived as recommended driving.

The report control unit 24 controls the monitor 14 to display the driving assistance information, which is the information of the recommended driving derived by the driving derivation unit 23. For example, the control monitor 14 displays an image of a target vehicle speed for passing through the intersection without stopping at the intersection, and displays an image of a deceleration command when stopping at the intersection is necessary.

The output unit 25 transmits the driving assistance information provided to the driver to the in-

vehicle devices

101a, 102a of the

rear vehicles

101, 102 via the communication unit 11. The transmitted information includes own vehicle information including information that the own vehicle 100 has a driving assistance function for deriving driving assistance information. The transmitted information is displayed on, for example, monitors of the

rear vehicles

101 and 102, and thus the drivers of the

rear vehicles

101 and 102 can recognize the reason for the current traveling mode of the preceding vehicle (the host vehicle 100). For example, it can be recognized that the own vehicle 100 predicts that the traffic signal 201 has changed from green to red and has decelerated.

Fig. 5 is a flowchart showing an example of processing executed by the controller 20 of fig. 3. The processing shown in this flowchart is started, for example, when the controller 20 detects that there are

rear vehicles

101, 102 that can perform inter-vehicle communication with the host vehicle 100 behind the host vehicle 100, and is repeatedly performed at a predetermined cycle corresponding to the operation cycle of the computer.

First, in S1 (S: processing step), traffic signal information and rear vehicle information are acquired via the communication unit 11, and position information obtained by the positioning sensor 12 is acquired. Whether the

rear vehicles

101, 102 satisfy the inter-vehicle distance condition (Δ L1 ≦ Δ La, Δ L3 ≦ Δ Lb) is determined, and rear vehicle information from the

rear vehicles

101, 102 that satisfy the inter-vehicle distance condition is acquired. Next, in S2, the total length L0 from the front end of the host vehicle 100 to the rear end of the rear vehicle 102 located at the rear end of the vehicle group 110 is calculated using the lengths of the

rear vehicles

101 and 102 included in the rear vehicle information.

Next, in S3, it is determined whether or not recommended driving recommended to the driver is derived. When the own vehicle 100 passes through the traffic signal 201, the recommended driving is derived from the traffic signal information. Therefore, the determination at S3 corresponds to the determination of whether or not the own vehicle 100 approaches the traffic signal 201. If S3 is affirmative (S3: YES), the process proceeds to S4, and if it is negative (S3: NO), S4 and S5 are skipped to end the process.

In S4, a control signal is output to the monitor 14, and driving assistance information, which is information for recommending driving, such as a target vehicle speed and a deceleration command, is displayed on the monitor 14. Next, in S5, the driving assistance information displayed on the monitor 14 is transmitted to the in-

vehicle devices

101a and 102a of the

rear vehicles

101 and 102 via the communication means 11, and the processing is ended.

The operation of the driving assistance device 10 of the present embodiment will be described more specifically. As shown in fig. 2A, when the host vehicle 100 and the

rear vehicles

101 and 102 connected to the host vehicle 100 travel as the vehicle group 110, the monitor 14 of the host vehicle 100 displays the target vehicle speed based on the traffic signal information (S4). The target vehicle speed is a vehicle speed that can pass from the host vehicle 100 to the rear vehicle 102 without stopping at the intersection, and is calculated based on the entire length L0 of the vehicle group 110. Thus, the

rear vehicles

101 and 102 can travel with the switching of the traffic signal 201 predicted, as with the vehicle having the driving assistance function, even though they do not have the driving assistance function based on the traffic signal information.

On the other hand, even if the traffic signal 201 is currently green, if it is determined that the traffic signal 201 has changed to yellow or red before the vehicle group 110 passes through the intersection, a deceleration command is displayed on the monitor 14 of the host vehicle 100 (S4). At this time, the driving assistance information for the deceleration command of the host vehicle 100 is transmitted to the in-

vehicle devices

101a and 102a of the rear vehicles 101 and 102 (S5). This allows the driver of the

rear vehicle

101, 102 to recognize the reason when the host vehicle 100 decelerates, and to perform the driving operation without giving an uncomfortable feeling.

In this case, the drivers of the

rear vehicles

101 and 102 recognize that a deceleration command is output to the driver of the host vehicle 100, and the vehicle group 110 can be configured to decelerate as a whole while ensuring the inter-vehicle distance by starting deceleration in order from the rear vehicle 102. The monitor 14 of the host vehicle 100 also displays information on the remaining time until the traffic signal 201 is switched to green when the host vehicle 100 is stopped at a red light. This information is also transmitted to the in-

vehicle devices

101a, 102a of the

rear vehicles

101, 102 in the parking state via the communication unit 11. Thus, when the traffic signal 201 is switched from red to green, the host vehicle 100 and the

rear vehicles

101 and 102 can start at the same time, and the vehicle group 110 can start smoothly.

The present embodiment can provide the following effects.

(1) The driving assistance device 10 includes: a communication unit 11; an information acquisition unit 21 (a traffic signal information acquisition unit, a rear vehicle information acquisition unit, and a position information acquisition unit) that acquires, via the communication unit 11, traffic signal information including switching information of the traffic signal 201 and rear vehicle information including length information of the rear vehicles 101 and 102 traveling behind the host vehicle 100, and that acquires position information indicating the position of the host vehicle 100 with respect to the traffic signal 201; a length calculation unit 22 that calculates the overall length L0 from the front end of the running host vehicle 100 to the rear end of the rear vehicle 102, based on the length information of the rear vehicle 102 acquired by the information acquisition unit 21; a driving derivation unit 23 that derives driving assistance information including a target vehicle speed or a target acceleration of the vehicle 100 for the entire vehicle including the vehicle 100 and the rear vehicles 101 and 102 to pass through or stop at an intersection where the traffic signal 201 is installed, based on the traffic signal information and the position information acquired by the information acquisition unit 21 and the entire length L0 calculated by the length calculation unit 22; and an output unit 25 that transmits driving assistance information provided to the driver of the host vehicle 100 to the rear vehicles 101 and 102 via the communication unit 11 (fig. 3).

With this configuration, the driver of the

rear vehicles

101 and 102 can notice that the host vehicle 100 is driving based on the traffic signal information. As a result, when the host vehicle 100 decelerates despite the fact that the traffic signal 201 in front is green, it is possible to prevent the driver of the

rear vehicles

101 and 102 from feeling uncomfortable. Therefore, since the

rear vehicles

101 and 102 having no driving assistance function based on the traffic signal information are connected to the host vehicle 100 having the driving assistance function based on the traffic signal information and travel, the

rear vehicles

101 and 102 can smoothly travel at the intersection where the traffic signal 201 is installed without discomfort, as in the host vehicle 100.

(2) The driving assistance device 10 further includes a monitor 14 (fig. 3) that reports the driving assistance information derived by the driving derivation unit 23 to the driver of the host vehicle 100. Thus, the driver of the host vehicle 100 can easily recognize a target vehicle speed or the like for causing the entire vehicle group 110 including the host vehicle 100 and the

rear vehicles

101 and 102 to pass through the intersection. As a result, the host vehicle 100 and the

rear vehicles

101 and 102 can integrally pass through the intersection where the traffic signal 201 is installed, as if they were one large vehicle 110a.

(3) The own vehicle information transmitted from the output unit 25 via the communication unit 11 includes the driving assistance information derived by the driving derivation unit 23. This enables the driver of the

rear vehicles

101 and 102 to perform the acceleration and deceleration operation of the

rear vehicles

101 and 102 at an appropriate timing.

The above embodiment can be modified into various modes. Several modifications will be described below. In the above embodiment, the information acquiring unit 21 acquires the traffic signal information, the position information, and the rear vehicle information, but the configuration of the information acquiring unit 21, that is, the configuration of the traffic signal information acquiring unit, the position information acquiring unit, and the rear vehicle information acquiring unit is not limited to the above configuration. That is, the configuration of the traffic signal information acquisition unit may be any configuration as long as it is a configuration for acquiring traffic signal information including switching information of the traffic signal 201 via the communication unit 11. The configuration of the position information acquisition unit may be any configuration as long as it is a configuration to acquire position information indicating the position of the vehicle 100 with respect to the traffic signal 201. The configuration of the rear vehicle information acquisition unit may be any configuration as long as it is a configuration for acquiring rear vehicle information including length information of the

rear vehicles

101 and 102 traveling behind the host vehicle 100 via the communication means 11.

In the above embodiment, the information acquisition unit 21 acquires the traffic signal information on the traffic signal installed at the intersection, but the traffic signal information may be information on a traffic signal at a crosswalk or the like, and the location where the traffic signal is installed is not limited to the intersection. In the above embodiment, the driving derivation unit 23 derives the recommended driving recommended to the driver based on the traffic signal information acquired by the information acquisition unit 21, the position information of the host vehicle 100, and the entire length of the vehicle group 110 calculated by the length calculation unit 22. Specifically, the driving assistance information including the target vehicle speed and the target acceleration is derived, but other recommended driving such as a command for a lane change may be derived, and the configuration of the deriving unit is not limited to the above configuration.

In the above embodiment, the output unit 25 transmits the driving assistance information provided to the driver of the host vehicle 100 to the

rear vehicles

101 and 102 via the communication unit 11, but may transmit other information together as long as the host vehicle information including information that the host vehicle has a driving assistance function for deriving the driving assistance information is transmitted to the

rear vehicles

101 and 102 via the communication unit 11. Therefore, the own vehicle information transmitted to the

rear vehicles

101 and 102 is not limited to the above information, and the configuration of the output unit 25 is not limited to the above configuration. In the above embodiment, the report control unit 24 reports the driving assistance information derived by the driving derivation unit 23 to the driver via the monitor 14, but may report the driving assistance information to the driver by voice output or the like, and the configuration of the report unit is not limited to the above configuration.

In the above embodiment, the host vehicle 100 is configured as a manually driven vehicle, but may be configured as an automatically driven vehicle having an automatic driving function. In this case, the controller 20 may control the running operation of the host vehicle 100 based on the driving assistance information and may not display the driving assistance information on the monitor 14.

The present invention can also be used as a driving assistance method including the steps of: acquiring, by the communication unit 11, traffic signal information including switching information of the traffic signal 201; acquiring position information indicating a position of the vehicle relative to the traffic signal 201; acquiring rear vehicle information including length information of a rear vehicle traveling behind the host vehicle via the communication unit 11; calculating an overall length from a front end of the host vehicle to a rear end of the rear vehicle based on the acquired length information of the rear vehicle; deriving driving assistance information including a target vehicle speed or a target acceleration of the host vehicle for the entire vehicle including the host vehicle and the rear vehicle to pass through or stop at or near the point where the traffic signal 201 is provided, based on the acquired traffic signal information, the acquired position information, and the calculated overall length; and transmitting own vehicle information including information that the own vehicle has a driving assistance function for deriving the driving assistance information to the rear vehicle through the communication unit 11.

One or more of the above embodiments and modifications may be arbitrarily combined, or modifications may be combined with each other.

The present invention can suppress the driver of the rear vehicle having no driving assistance function based on the traffic signal information from feeling uncomfortable due to the movement of the front vehicle.

The present invention has been described above with reference to preferred embodiments, but it will be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of the disclosure of the following claims.

Claims

1. A driving assistance device is characterized by comprising:

a communication unit (11);

a traffic signal information acquisition unit that acquires, via the communication unit (11), traffic signal information including switching information of a traffic signal (201);

a position information acquisition unit that acquires position information indicating the position of the vehicle relative to the traffic signal (201);

a rear vehicle information acquisition unit that acquires rear vehicle information including length information of a rear vehicle that runs behind the host vehicle, via the communication unit (11);

a length calculation unit (22) that calculates the overall length from the front end of the host vehicle to the rear end of the rear vehicle, based on the length information of the rear vehicle acquired by the rear vehicle information acquisition unit;

a derivation unit (23) that derives driving assistance information including a target vehicle speed or a target acceleration of the vehicle, which is used for the entire vehicle including the host vehicle and the rear vehicle to pass through a point where the traffic signal (201) is installed or to stop in front of the point, on the basis of the traffic signal information acquired by the traffic signal information acquisition unit, the position information acquired by the position information acquisition unit, and the entire length calculated by the length calculation unit (22); and

and an output unit (25) that transmits, to the rear vehicle via the communication unit (11), vehicle information including information that the vehicle has a driving assistance function for deriving the driving assistance information.

2. The driving assist device according to claim 1,

the vehicle further comprises a reporting unit (14), wherein the reporting unit (14) reports the driving assistance information derived by the deriving unit (23) to the driver of the host vehicle.

3. The driving assistance apparatus according to claim 1 or 2,

the own vehicle information transmitted by the output unit (25) through the communication means (11) includes the driving assistance information derived by the derivation unit (23).

4. The driving assist device according to claim 1 or 2,

further comprising a distance detector (13), wherein the distance detector (13) detects the distance from the host vehicle to the rear vehicle,

the rear vehicle information acquisition unit acquires the rear vehicle information on the rear vehicle for which the distance detected by the distance detector (13) is within a predetermined distance.

5. The driving assist device according to claim 4,

the rear vehicle includes a first rear vehicle (101) that runs behind the host vehicle and a second rear vehicle (102) that runs behind the first rear vehicle (101),

the rear vehicle information acquisition unit acquires the rear vehicle information on the first rear vehicle (101) and the second rear vehicle (102) when a distance from the host vehicle to the first rear vehicle (101) is within a first predetermined distance (Δ La) and a distance from the first rear vehicle (101) to the second rear vehicle (102) is within a second predetermined distance (Δ Lb).

6. A driving assistance method characterized by comprising the steps of:

acquiring, by a communication unit (11), traffic signal information including switching information of a traffic signal (201);

acquiring position information indicating a position of the vehicle relative to the traffic signal (201);

acquiring rear vehicle information including length information of a rear vehicle traveling behind the host vehicle, by the communication unit (11);

calculating an overall length from a front end of the host vehicle to a rear end of the rear vehicle based on the acquired length information of the rear vehicle;

deriving driving assistance information including a target vehicle speed or a target acceleration of the host vehicle for the entire vehicle including the host vehicle and the rear vehicle to pass through or stop in front of a point where the traffic signal (201) is installed, based on the acquired traffic signal information, the acquired position information, and the calculated overall length; and

the communication means (11) transmits, to the rear vehicle, own vehicle information including information that the own vehicle has a driving assistance function for deriving the driving assistance information.